ViewSonic VA902B Service Manual - Page 13

7. Key Parts Pin Assignment 7.1 IC802 (TOP246Y, Power Control IC) Pin Symbol I/O Description 1 C I Control 2 L I Line Sense 3 X I External Current Limit 4 S O Source of MOSFET(GND) 5 F I Frequency 6 D I Drain of MOSFET 7.2 IC501 (OZ9910G, CCFL inverter controller IC) Pin No. Symbol I/O Description 1 NDRV4 O Bottom MOSFET gate drive output in dual forward converter 2 PGND High-current power ground 3 NDRV2 O Bottom MOSFET gate drive output in dual forward converter 4 GNDA Low-current signal ground 5 CT I Timing capacitor of high frequency oscillator 6 LCT I Timing capacitor of set LPWM frequency 7 ADJ I Control command input -DC 8 ENA I Enable input 9 VSEN I Voltage sense feedback 10 CMP_SST I Soft start and loop compensation capacitor 11 ISEN I Current sense feedback 12 VREF O Reference voltage output 13 VIN I Supply voltage for IC 14 HSB I High side driver buffer output 15 PDRV3 O Top MOSFET gate drive output in dual forward converter 16 PDRV1 O Top MOSFET gate drive output in dual forward converter 7.3 U104 (TSU16AK) Pin Symbol 1 LVBOM 2 GND 3 BYPASS 4 NC 5 NC 6 BUSTYPE 7 NC 8 NC 9 NC 10 GND 11 VDDP 12 NC 13 NC 14 NC 15 NC 16 NC 17 NC 18 VDDC 19 GND I/O Description O B-Link Negative LVDS Differential Data Output Ground For External Bypass Capacitor Not connected Not connected IN Low : Serial bus; High : Direct bus Not connected Not connected Not connected Ground O Digital Output Power Not connected Not connected Not connected Not connected Not connected Not connected I Digital Core Power Ground ViewSonic Corporation Confidential - Do Not Copy VA902/b 10